Fluid Mechanics
Introduction Of Fluid Machinary:
What is Fluid Machine:
- A fluid machine is a device which converts the energy stored by a fluid into mechanical energy or vice versa.The energy stored by a fluid mass appears in the form of potential, kinetic and Intermolecular energy.
- The mechanical energy, on the other hand, is usually transmitted by a rotating shaft.Machines using liquid (mainly water, for almost all practical purposes) are termed as hydraulic machines.
- The fluid machines use either liquid or gas as the working fluid depending upon the purpose.
- The machine transferring mechanical energy of rotor to the energy of fluid is termed as a pump when it uses liquid, and is termed as a compressor or a fan or a blower, when it uses gas.
- The compressor is a machine where the main objective is to increase the static pressure of a gas. Therefore, the mechanical energy held by the fluid is mainly in the form of pressure energy.
- Fans or blowers, on the other hand, mainly cause a high flow of gas, and hence utilize the mechanical energy of the rotor to increase mostly the kinetic energy of the fluid.In these machines, the change in static pressure is quite small.
- For all practical purposes, liquid used by the turbines producing power is water, and therefore, they are termed as water turbines or hydraulic turbines .
- Turbines handling gases in practical fields are usually referred to as steam turbine, gas turbine, and air turbine depending upon whether they use steam, gas (the mixture of air and products of burnt fuel in air) or air.
Fluid machine may be divided into two groups;
A) Positive displacement
- piston pump
- peristaltic pump
- gear pump
- two-lobe rotary pump
- screw pump
- Jet pumps
B) Turbo machines
- axial-flow (propeller pump)
- radial-flow (centrifugal pump)
- mixed-flow (both axial and radial flow)
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